In conventional wireless communication systems, a single Base Station (BS) services Mobile Stations (MSs) in a certain area. However, as demand for a data service rapidly grows, it is necessary to develop techniques of higher transmission efficiency and transfer rate.
In response to such a demand, an advanced mobile communication system ensures additional transmission resources via a heterogeneous network which maintains the existing cellular coverage and additionally installs various BSs, and makes an effort to achieve high transmission efficiency by applying small cell technology for servicing a narrow area against the existing cellular environment. In connection with the heterogeneous network and the small cell technology, researches are conducted to enhance frequency utilization and to lower power consumption by adopting the small cell technology using the additional frequency resource with the existing macrocell maintained, Further, researches are conducted to minimize overhead and to maximize the transmission efficiency by reusing some control channels including a synchronization channel of the existing macrocell in the additional small cell.
However, when the synchronization channel of the existing macrocell is reused in the additional small cell, the overhead can be reduced and the data rate can increase. Disadvantageously, it is hard for the legacy MS to detect the small cell and to carry out the synchronization. Thus, when the small cell does not have the synchronization channel or the legacy MS cannot recognize the synchronization channel by itself, what is needed is a solution enabling the MS to detect the small cell and to communicate using the small cell.